Mesothelioma Diagnosis

Another interesting study is called, Immunohistochemical Analysis of the p16INK4 Cyclin-Dependent Kinase Inhibitor in Malignant Mesothelioma – JNCI J Natl Cancer Inst (1995) 87 (24): 1870-1875 by Robert A. Kratzke, Gregory A. Otterson, Clint E. Lincoln, Stephen Ewing, Herbert Oie, Joseph Geradts and Frederic J. Kaye. Here is an excerpt: Abstract – Background: The identification in 1994 of the CDKN2 gene as a target for mutations in a wide range of human cancers, including malignant mesothelioma, has been controversial because subsequent studies have detected a lower frequency of CDKN2 gene mutations in primary tumors than in cultured cell lines. These reports raised the hypothesis that another gene, distinct from CDKN2, might be the target of the chromosome 9p21 deletions frequently observed in these tumors. Purpose: To address whether inactivation of CDKN2 function is an essential event in the etiology of malignant mesothelioma, we examined p16INK4 protein expression in primary thoracic mesotheliomas, in nonmalignant pleural tissues, and in independent mesothelioma cell lines. We also studied the growth rate of tumor cell lines following stable transfection of CDKN2 gene. Methods: Retinoblastoma (Rb) and p16INK4 protein expression was determined by immunohistochemical analysis from archival paraffin specimens of 12 primary thoracic mesotheliomas and a nonmalignant pleural biopsy specimen. In addition, protein immunoblot analysis for Rb and p16INK4 expression was conducted on 15 independent mesothelioma cell lines, and the ability of a transfected CDKN2 gene to suppress the growth of the mesothelioma cell lines H2373 and H2461 in vitro was examined. Results: We demonstrated abnormal p16INK4 expression in 12 of 12 primary mesothelioma specimens and in 15 of 15 mesothelioma cell lines. All tumor specimens and the tumor cell lines showed expression of wild-type Rb protein. In addition, we have confirmed the ability of a transfected CDKN2 gene to suppress growth of two independent mesothelioma cell lines. Conclusions: Immunohistochemical analysis of the p16INK4 gene product is feasible in archival biopsy samples. With this analysis, CDKN2 gene inactivation can be determined in tumors that are contaminated with nonmalignant cells. Furthermore, since loss of p16INK4 protein expression can result from both genetic (gene mutations) and epigenetic (abnormal DNA hypermethylation) mechanisms, as we and others have shown recently, examination of protein expression is a highly sensitive method for analyzing the CDKN2 status in large numbers of tumor samples.
Another interesting study is called, Phase I Clinical and Pharmacokinetic Study of Pemetrexed and Carboplatin in Patients With Malignant Pleural Mesothelioma By Andy Hughes, Paula Calvert, Ashraf Azzabi, Ruth Plummer, Rob Johnson, Jim Rusthoven, Melanie Griffin, Kevin Fishwick, Alan V Boddy, Mark Verrill, Hilary Calvert – Journal of Clinical Oncology, Vol 20, Issue 16 (August), 2002: 3533-3544. Here is an excerpt: ABSTRACT – PURPOSE: To determine the maximum tolerated dose (MTD) of pemetrexed and carboplatin given in combination, to derive a recommended dose for phase II studies, and to explore its efficacy. We assessed toxicities and explored the activity of the drug combination exclusively in patients with malignant pleural mesothelioma (MPM). The pharmacokinetics of both agents was investigated.

PATIENTS AND METHODS: Twenty-seven patients (23 male, four female) with MPM were treated on five escalating dose levels. Doses ranged from pemetrexed 400 mg/m2 (as a 10-minute intravenous infusion), followed by carboplatin area under the plasma concentration-time curve (AUC) 4 mg/mLmin (as a 30-minute intravenous infusion) to pemetrexed 500 mg/m2, carboplatin AUC 6 mg/mLmin. All patients had a World Health Organization performance status of 1. A total of 163 courses of treatment were administered (median, six; range, one to 10).

Another interesting study is called, “Immunohistochemical Analysis of the p16INK4 Cyclin-Dependent Kinase Inhibitor in Malignant Mesothelioma” – JNCI J Natl Cancer Inst (1995) 87 (24): 1870-1875 by Robert A. Kratzke, Gregory A. Otterson, Clint E. Lincoln, Stephen Ewing, Herbert Oie, Joseph Geradts and Frederic J. Kaye.  Here is an excerpt: “Abstract – Background: The identification in 1994 of the CDKN2 gene as a target for mutations in a wide range of human cancers, including malignant mesothelioma, has been controversial because subsequent studies have detected a lower frequency of CDKN2 gene mutations in primary tumors than in cultured cell lines. These reports raised the hypothesis that another gene, distinct from CDKN2, might be the target of the chromosome 9p21 deletions frequently observed in these tumors.  Purpose: To address whether inactivation of CDKN2 function is an essential event in the etiology of malignant mesothelioma, we examined p16INK4 protein expression in primary thoracic mesotheliomas, in nonmalignant pleural tissues, and in independent mesothelioma cell lines.

We also studied the growth rate of tumor cell lines following stable transfection of CDKN2 gene. Methods: Retinoblastoma (Rb) and p16INK4 protein expression was determined by immunohistochemical analysis from archival paraffin specimens of 12 primary thoracic mesotheliomas and a nonmalignant pleural biopsy specimen. In addition, protein immunoblot analysis for Rb and p16INK4 expression was conducted on 15 independent mesothelioma cell lines, and the ability of a transfected CDKN2 gene to suppress the growth of the mesothelioma cell lines H2373 and H2461 in vitro was examined. Results: We demonstrated abnormal p16INK4 expression in 12 of 12 primary mesothelioma specimens and in 15 of 15 mesothelioma cell lines. All tumor specimens and the tumor cell lines showed expression of wild-type Rb protein. In addition, we have confirmed the ability of a transfected CDKN2 gene to suppress growth of two independent mesothelioma cell lines.  Conclusions: Immunohistochemical analysis of the p16INK4 gene product is feasible in archival biopsy samples. With this analysis, CDKN2 gene inactivation can be determined in tumors that are contaminated with nonmalignant cells. Furthermore, since loss of p16INK4 protein expression can result from both genetic (gene mutations) and epigenetic (abnormal DNA hypermethylation) mechanisms, as we and others have shown recently, examination of protein expression is a highly sensitive method for analyzing the CDKN2 status in large numbers of tumor samples.”
Another interesting study is called, “Phase I Clinical and Pharmacokinetic Study of Pemetrexed and Carboplatin in Patients With Malignant Pleural Mesothelioma” 
By Andy Hughes, Paula Calvert, Ashraf Azzabi, Ruth Plummer, Rob Johnson, Jim Rusthoven, Melanie Griffin, Kevin Fishwick, Alan V Boddy, Mark Verrill, Hilary Calvert – Journal of Clinical Oncology, Vol 20, Issue 16 (August), 2002: 3533-3544.  Here is an excerpt: “ABSTRACT – PURPOSE: To determine the maximum tolerated dose (MTD) of pemetrexed and carboplatin given in combination, to derive a recommended dose for phase II studies, and to explore its efficacy. We assessed toxicities and explored the activity of the drug combination exclusively in patients with malignant pleural mesothelioma (MPM). The pharmacokinetics of both agents was investigated.

Another interesting study is called, “Induction of mesothelioma in p53 mouse by intraperitoneal application of multi-wall carbon nanotube” by Atsuya Takagi, Akihiko Hirose, Tetsuji Nishimura, Nobutaka Fukumori, Akio Ogata, Norio Ohashi, Satoshi Kitajima and Jun Kanno – The Journal of Toxicological Sciences Vol. 33 (2008) , No. 1 February 105-116.  Here is an excerpt: “ABSTRACT-  Nanomaterials of carbon origin tend to form various shapes of particles in micrometer dimensions. Among them, multi-wall carbon nanotubes (MWCNT) form fibrous or rod-shaped particles of length around 10 to 20 micrometers with an aspect ratio of more than three. Fibrous particles of this dimension including asbestos and some man-made fibers are reported to be carcinogenic, typically inducing mesothelioma. Here we report that MWCNT induces mesothelioma along with a positive control, crocidolite (blue asbestos), when administered intraperitoneally to p53 heterozygous mice that have been reported to be sensitive to asbestos.

Our results point out the possibility that carbon-made fibrous or rod-shaped micrometer particles may share the carcinogenic mechanisms postulated for asbestos. To maintain sound activity of industrialization of nanomaterials, it would be prudent to implement strategies to keep good control of exposure to fibrous or rod-shaped carbon materials both in the workplace and in the future market until the biological/ carcinogenic properties, especially of their long-term biodurability, are fully assessed.”